Etching reaction device with protrusions

ABSTRACT

An etching reaction device ( 3 ) includes an etching reaction chamber ( 30 ), and a number of protrusions ( 301 ) arranged on the bottom of the etching reaction chamber. Thus it can economize the etching time and quickly complement the concentration of the etching liquid near to a wafer ( 7 ). The protrusions can reduce the capability of the etching reaction chamber, thus it can economize the etching liquid.

FIELD OF THE INVENTION

The present invention relates to an etching reaction device typically used for etching a wafer such as a semiconductor wafer.

BACKGROUND

In a typical process of manufacturing a semiconductor wafer, a film is formed on the semiconductor wafer. If the film is not uniform or a thickness of the film is not according to specifications, the film is generally removed altogether.

Nowadays, popular etching methods include dry etching methods and wet etching methods. A typical etching reaction device for wet etching is shown in FIG. 3. The etching reaction device 1 uses etching liquid that chemically reacts with the film, whereby the film can be removed.

The etching reaction device 1 includes an etching reaction chamber 10, an etching liquid transporting pipe 12, an etching liquid entrance 15, and a plurality of rollers 16. The etching liquid entrance 15 is set at a bottom of the etching reaction chamber 10, and is connected with the etching liquid transporting pipe 12. The rollers 16 are set inside the etching reaction chamber 10.

When a wafer 5 is to be etched by the etching reaction device 1, the wafer 5 is set on the rollers 16 such that the wafer 5 can slide along the rollers 16. The etching liquid enters the etching reaction chamber 10 through the etching liquid transporting pipe 12 and the etching liquid entrance 15. The etching liquid reaches the wafer 5, and chemically reacts with the film of the wafer 5. The film of the wafer 5 transforms into another substance, which substance dissolves in the etching liquid. Thus the film is removed from the wafer 5.

The wafer 5 is set on the rollers 16, and the film of the wafer 5 chemically reacts only with etchant in the etching liquid has reached the wafer 5. Thus the concentration of the etching liquid near the wafer 5 is lower than that in other areas of the etching reaction chamber 10. The higher concentration etching liquid in the other areas of the etching reaction chamber 10 travels toward the wafer 5 and replenishes and replaces the lower concentration etching liquid at the wafer 5. That is, higher concentration etching liquid flows until it is blocked by sides of the etching reaction chamber 10, whereupon the higher concentration etching liquid rises toward the wafer 5. Thus circulation of etching liquid occurs because of the convection phenomenon.

However, particularly in cases where the etching reaction chamber 10 is large, the etching liquid takes a long time to flow from the etching liquid entrance 15 to the sides of the etching reaction chamber 10. That is, the efficiency of circulation of the etching liquid is low. The etching liquid near the wafer 5 may not be timely replenished and replaced, and so the wafer 5 may not be etched uniformly.

What is needed, therefore, is a new etching reaction device which overcome the above-described problems.

SUMMARY

In one embodiment, an etching reaction device comprises an etching reaction chamber, and a plurality of protrusions arranged on the bottom of the etching reaction chamber.

The protrusions arranged on the bottom of the etching reaction chamber are provided for redirecting a flow of etching liquid. When the etching liquid flows in the etching reaction chamber, it is blocked by the protrusions and rises toward a wafer. The plural protrusions help plural circulations of etching liquid because of the convection phenomenon. Therefore, the lower concentration etching liquid near the wafer is continuously replenished and replaced by higher concentration etching liquid traveling thereof from the other areas of the etching reaction chamber. Thus it can economize the etching time. And it can quickly complement the concentration of the etching liquid near to the wafer, thus the wafer is etched uniformly. The protrusions can reduce the capability of the etching reaction chamber. Thus, it can economize the etching liquid.

Other advantages and novel features will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic, cross-sectional view of an etching reaction device according to an exemplary embodiment of the present invention, together with a wafer placed therein.

FIG. 2 is an isometric view of the etching reaction device of FIG. 1, but not showing rollers thereof and not showing the wafer.

FIG. 3 is a schematic, cross-sectional view of a typical etching reaction device, together with a wafer placed therein.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1 and FIG. 2, an etching reaction device according to an exemplary embodiment of the present invention is shown. The etching reaction device 3 includes an etching reaction chamber 30, an etching liquid transport pipe 32, an etching liquid entrance 35, a plurality of rollers 36, and a plurality of protrusions 301.

The etching liquid entrance 35 is set at the bottom 39 of the etching reaction chamber 30, and is connected with the etching liquid transporting pipe 32. The plurality of rollers 16 is set inside the etching reaction chamber 30. The plurality of protrusions 301 is set on the bottom 39 of the etching reaction chamber 30.

When a wafer 7 is etched by the etching reaction device 3. The wafer 7 is set on the rollers 36, and can slide along the rollers 36. The etching liquid enters the etching reaction chamber 30 through the etching liquid transporting pipe 32 and the etching liquid entrance 35. The etching liquid reaches the wafer 7, and chemically reacts with a film of the wafer 7. The film of the wafer 7 is transformed into another substance, which substance can be dissolved in the etching liquid. Thus the film can be removed from the wafer 7.

The film of the wafer 7 chemically reacts with etchant in the etching liquid which has reached the wafer 7. Thus the concentration of the etching liquid near the wafer 7 is lower than that in other areas of the etching reaction chamber 30. The higher concentration etching liquid in the other areas of the etching reaction chamber 30 travels toward the wafer 7 and replenishes and replaces the lower concentration etching liquid at the wafer 7.

The protrusions 301 arranged on the bottom 39 of the etching reaction chamber 30 are provided for redirecting a flow of the etching liquid. When the etching liquid flows in the etching reaction chamber 30, it is blocked by the protrusions 301 and rises toward the wafer 7. The plural protrusions 301 help generate plural circulations of etching liquid, because of the convection phenomenon. A distance between each protrusion 301 and the etching liquid entrance 35 is shorter than a distance between the corresponding side 33 of the etching reaction chamber 30 and the etching liquid entrance 35. Thus the etching liquid flowing from the etching liquid entrance 35 flows to each protrusion 301 quicker than it does to the corresponding side 33. This can reduce the time required to etch the wafer 7. In addition, as described above, the lower concentration etching liquid near the wafer 7 is continuously replenished and replaced by higher concentration etching liquid traveling thereto from the other areas of the etching reaction chamber 30. This helps ensure that the wafer 7 is etched uniformly.

Because the cubage of the etching reaction chamber 30 is aptotic. The protrusions 301 on the bottom 39 of the etching reaction chamber 30 reduce the capacity of the etching reaction chamber 30 while simultaneously providing for improved flow of the etching liquid. Accordingly, the amount of etching liquid required is reduced. That is, the etching reaction device 3 can economize on the use of etching liquid.

In the exemplary embodiment, the protrusions 301 are made of polyvinylidene difluoride, and are tapered in cross-section. The protrusions 301 can, for example, alternatively be step-shaped, columnar, triangular in cross-section, or rectangular in cross-section.

It is to be further understood that even though numerous characteristics and advantages of various embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

1. An etching reaction device, comprising: an etching reaction chamber; and a plurality of protrusions arranged on a bottom of the etching reaction chamber.
 2. The etching reaction device as claimed in claim 1, further comprising an etching liquid entrance associated with the bottom of the etching reaction chamber.
 3. The etching reaction device as claimed in claim 2, further comprising an etching liquid transport pipe connected with the etching liquid entrance.
 4. The etching reaction device as claimed in claim 1, further comprising a plurality of rollers in the etching reaction chamber.
 5. The etching reaction device as claimed in claim 1, wherein the protrusions are made of polyvinylidene difluoride.
 6. The etching reaction device as claimed in claim 1, wherein the protrusions are step-shaped.
 7. The etching reaction device as claimed in claim 1, wherein the protrusions are columnar.
 8. The etching reaction device as claimed in claim 1, wherein the protrusions tapered in cross-section.
 9. The etching reaction device as claimed in claim 1, wherein the protrusions are triangular in cross-section.
 10. The etching reaction device as claimed in claim 1, wherein the protrusions are rectangular in cross-section.
 11. A method of making etching comprising: providing an etching device with an etching reaction chamber; forming a plurality of protrusions on at least one interior surface of said etching device in communication with the etching reaction chamber; and injecting etching liquid into the chamber; wherein said protrusions performs at least one of functions of even distribution and convection.
 12. The method as claimed in claim 11, wherein the protrusions surround a liquid entrance of said etching liquid.
 13. The method as claimed in claim 11, wherein the protrusions and a liquid entrance of the etching liquid are located on a same interior face of the etching device.
 14. The method as claimed in claim 13, wherein a wafer ready for etching is spatially located above both said liquid entrance and said protrusions.
 15. An etching reaction device, comprising: an etching reaction chamber; a plurality of protrusions disposed in the etching reaction chamber; and a wafer located above said protrusions; wherein etching liquid moves in said chamber under effects derived from said protrusions.
 16. The etching reaction device as claimed in claim 15, wherein said protrusions are formed on a bottom interior face of the etching device.
 17. The etching reaction device as claimed in claim 16, wherein an etching liquid entrance is located on the bottom interior face. 